Final answer:
To find the critical points of a function and determine whether they correspond to a local minimum or maximum, follow these steps: Find the derivative, solve for x when the derivative equals zero, take the second derivative, and substitute the critical points into the second derivative.
Step-by-step explanation:
To find the critical points of a function and determine whether they correspond to a local minimum or maximum, you need to follow these steps:
- Find the derivative of the function.
- Solve for x when the derivative equals zero to find the critical points.
- Take the second derivative of the function.
- Substitute the critical points into the second derivative.
- If the second derivative is positive at a critical point, it corresponds to a local minimum. If the second derivative is negative at a critical point, it corresponds to a local maximum.
For example, let's say we have the function f(x) = x^2 - 6x + 8. The derivative is f'(x) = 2x - 6, and the second derivative is f''(x) = 2. Setting the derivative equal to zero, we get 2x - 6 = 0, which gives us x = 3. Substituting x = 3 into the second derivative, we get f''(3) = 2, which is positive. Therefore, x = 3 corresponds to a local minimum.